Abstract

The mining history of Utah really begins with the arrival of the Latter Day Saints in the Salt Lake valley in 1847 and the discovery of gold in California the following year. Little is known of prior Native American efforts at exploiting Utah’s mineral resources, however, several of the earliest recorded discoveries by the pioneers apparently resulted from leadership by aboriginal guides. The massive influx of Forty-Niners resulted in a scattering of mineral discoveries across the Great Basin as the prospectors traveled to the California gold fields, e.g. placer gold was located near the Comstock lode in 1850. Later, a wave of discoveries fanned out to the east from the gold fields of California as disenchanted prospectors went further a field in search of their fortunes. The 1860s saw the discovery of new mining districts and ore deposits throughout Utah as a result of prospecting trips by the Third California Infantry under Colonel Patrick E. Connor during the Civil War, e.g. Bingham Canyon and Park City. The arrival of the railroads in the mining districts in the 1870s sent off a boom in both base and precious metal production from these newly discovered camps.

Utah’s mineral discoveries continued into the first half of the 20^th century, accompanied by a surge in metal production. The eastern Great Basin’s increasing ore production turned Salt Lake City into the intermountain west’s milling, smelting, and transportation center. This period also saw significant innovations in mining and metallurgy, led by Daniel Jackling’s important pioneering work in the bulk mining and milling of porphyry copper ores at Bingham Canyon. A huge emphasis on metal production was placed on the mines by the Allies efforts in the two World Wars. This prioritization generated renewed prospecting and exploration activities leading to additional discoveries mostly within known mining camps, e.g. the East Tintic district. Utah’s lead, zinc, and silver production all reached their peaks during this half-century.

The later half of the 1900s were a difficult time for Utah’s mining industry, however it also saw the rise of organized mineral exploration groups, e.g. Kennecott Exploration Company. The new demands of nuclear power and atomic warfare set off uranium prospecting rushes to southeastern Utah in the 1950s and 1960s and an accompanying bull market on the Salt Lake penny stock exchange. However, uranium production had tailed off by the 1980s. The Clean Air act of 1971 forced the closure of all of Utah’s base metal smelters and the majority of the base metal mines of the Great Basin closed with them. The beryllium deposits near Topaz Mountain (1968) and the magnesium production from Great Salt Lake brines (1972) began during this period and have continued to date. The sharp rise in the price of gold in the late 1970s led to renewed gold exploration programs in the 1980s and early 1990s. This effort resulted in the discovery and opening of several new gold mines in Utah using open-pit mining and the new cyanide heap leach technology that had been developed during this period, e.g. Barneys Canyon and Mercur. Utah’s gold and copper production peaked in the 1990s as a result of these new gold operations and the continuing production expansions at the Bingham Canyon operations.

The new century has seen the closure of nearly all of the metal mines in Utah. However, gold and silver production has continued in the western Great Basin, most prominently along the Carlin and Battle Mountain trends in Nevada. The Bingham Canyon porphyry system remains Utah’s most important source of metal and appears to be set for at least another decade of copper-gold-molybdenum-silver production.